A state lawmaker has pulled a proposed tax on sugary soda from the legislative agenda but plans to bring the idea back next year. Representative Edith Ajello, a Providence Democrat, said that not enough supporters were available to address lawmakers during a hearing Wednesday. The proposal would add a tax of one penny per ounce to the cost of regular soda or other sugar-sweetened drinks. Ajello wants the revenue to fight ­obesity, diabetes, and other public health threats.